First off, big fan of your work. I have noticed in your last Q+A here as well as in interviews that you tend to favour the 421/ 57 combo on guitar amps and will normally sum them to a single track.

I was wondering if you can elaborate on this: do you tend to favour one over the other in the blend? Any 'go-to' mic placements as a starting point? And any speakers or amps you find just to jive with this setup (I see you do it a lot with older Marshall's)?

Also, do you sum to one track in order to make a commitment and keep things moving forward, or is there more madness to your methods?